Electronically Modulated FeNi Composite by CeO2 Porous Nanosheets for Water Splitting at Large Current Density

Ming-Yu Ding, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China
Wen-Jie Jiang, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China
Tian-Qi Yu, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China
Xiao-Yan Zhuo, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China
Xiao-Jing Qin, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China
Shi-Bin Yin, Guangxi Key Laboratory of Electrochemical Energy Materials, College of Chemistry and Chemical Engineering, Guangxi University, 100 Daxue Road, Nanning 530004, China

Abstract

Exploiting highly activity and non-noble metal bifunctional catalysts at large current density is significant for the advancement of water electrolysis. In this work, CeO2 electronically structure modulated FeNi bimetallic composite porous nanosheets in-situ grown on nickel foam (NiFe2O4-Fe24N10-CeO2/NF) is synthesized. Electrochemical experiments show that NiFe2O4-Fe24N10-CeO2/NF exhibits outstanding oxygen and hydrogen evolution reaction (OER and HER) activity (η1000 = 352 mV and η1000 = 429 mV). When assembled into a two-electrode system for overall water splitting (OWS), it only needs a low cell voltage of 1.81 V to drive 100 mA cm−2. And it can operate stably at ±500 mA cm-2 over 30 h toward OER, HER and OWS without significant activity changes. The reason could be assigned to the electronic modulating of CeO2 on FeNi composite, which can boost the intrinsic activity and optimize the adsorption of reaction intermediates. Moreover, the porous nanosheets in-situ grown on NF could enhance the contact of active site with electrolyte and facilitate the gas release, thus improving its chemical and mechanical stability. This study highlights a novel approach to design bifunctional non-noble metal catalysts for water splitting at large current density.